Arrakis/DE
Arrakis is a planet which belongs to the Canopus system with many unique properties. Planetal characteristics Arrakis has a highly eccentric orbit around the Canopus star. For this, resposnible are Menaris, in combination with Extaris. Because of the large axial tilt, the polar axis of rotation processes a full revolution every 43,000 years. The planet's orbit was nearly circular and the axis of rotation was directed almost perpendicular to its ecliptic plane. Because of this there was no observable seasons other than a very slight advance and retreat of the poles. Arrakis has a density of 4.95 g/cm3 and an acceleration due to gravity of 864 cm/sec2. With such a gravitational attraction, the light gases such as hydrogen and helium have all but escaped into space. Atmospheric pressure at the equator is 760 mm, about average for a planet of this diameter and mass. Along with the local star group, there is an extensive dust cloud that permeates the Canopus near-space. This dust cloud was first detected by the Arrakian astronomer Chelin in 12704 AG. Evidence In 12984 AG correlated ice-age-like periods with the dust cloud opacity: the peculiar velocity of Canopus carried the cloud along with the planetary system through regions of varying cloud opacity. This had the resulting effect of reducing the radiation incidents on Arrakis, thus triggering near ice-age conditions. A similar, but even more severe shift in conditions occurred when Arrakis's third moon was destroyed by an asteroid/comet some 200,000 years ago. Magnetic field Arrakis has its own magnetic field which is severely contracted by Canopus, which emits an abnormally high flux of charged particles with imbedded magnetic-field segments. As a result, particles impinge directly on atmospheric molecules. No known effect on Arrakis weather has been proven to be a result of this interaction. Magnetic disturbances make the main field unreliable for navigation. Alternative means for direction finding, such as the paracompass, were developed to overcome this problem. Atmosphere The sky had an almost uniform dullness due to light scattering by the dust although occasionally, more often in the polar regions, it often appeared bluish. Thin, cirrus clouds occurred seasonally in the polar vicinity. Surface pressure, mean wind and temperature were also compatible with Neta 2C-53B guidelines: 1000 ± 5 millibars mean pressure, 286 ± 2 degrees absolute planetary mean temperature (annualized), and a mean global wind speed, standard height, of 20 ± 3 kilometers per hour. Composition The composition was quite similar to that of other Neta 2C-53B planets except that the amount of ozone was anomalously high and that of water vapor anomalously low. Before Kynes' transformation, major gaseous constituents were nitrogen (74.32%), oxygen (23.58%), and argon (1.01%). The most important trace gases were water vapor (less than 0.5%), carbon dioxide (0.035%), and ozone (0.52%). The excess ozone resulted to many atmospheric phenomena such as the Coriolis storm. Considerable dust was present in the atmosphere at all times. The atmospheric dust content was within the bounds of the Neta 2C-53B classification. Ptahtercicah (AG 9527) investigated the mechanisms of water vapor transport in terms of the minimum amount required to sustain any life and the correctness was confirmed using Arrakis as the test case. A slight amount of water vapor transported between the poles during the seasonal exchange. Climate The climate over most of the planet was hot and dry. Sub-freezing temperatures occurred only at the poles. Nights were generally and relatively cool. Weather Dust clouds (and the generating storms) were naturaly the dominant feature of Arrakis's weather. Dust was injected into the atmosphere as slender pillars by small vortex systems common to the desert portions of all Neta-class planets. They are caused daily by severe heating of the ground surface with cooler temperatures above and light wind. The hot air rose and pulled down the cooler air. The presence of a light wind was critical to me process since it was needed for the vortex to form. These phenomena ancient lore recognized as the spirits of ancestors. These whirls do not present a hazard to humans. Nefad (9156) proposed that the Coriolis storms were but a manifestation of the accumulation of multiple vortices associated with the turning of the wind vector by planetary rotation2. It is now known that Nefad's early considerations were overly simplistic and in part incorrect; Hohshas (11301) provided the basis from which our present understanding of these storms has been derived3. Coriolis forces did indeed play a major role, but the severity of me storm involves several factors, Ail had to combine in harmony to produce the greatest of these storms. An almost constant temperature difference (annual mean) of 27 degrees Celsius existed between the equator and the poles. This temperature difference caused atmospheric flow between equator and poles. On Arrakis the low was quite sluggish. The cooler air from the poles, being more dense, flowed along the surface, but was warmed quickly by surface radiation. In the northern hemisphere this flow was deflected westward, in the southern hemisphere eastward (Coriolis effect, planetary designation 3). Planetary rotation is in the B class, meaning that the general circulation was broken up into eddies. These are called cyclones and anticyclones, using the ancient Terran names. On all Neta-type planets with a 3 classification the cyclones produce storms. But the cyclones on Arrakis produced violent storms, primarily because of excess ozone. Ozone was concentrated only two kilometers above the surface. It was produced by Canopus's strong ultraviolet flux and absorbed much of the flux. The atmosphere thus experienced considerable heating at this low altitude. Temperature was high at the surface, decreased with altitude, but then increased when the ozone layer was encountered. Convection and advection associated with the cyclones was thus normally confined within two kilometers of the surface. This confinement greatly intensified storm severity. Surprisingly, the greatest Coriolis storms on Arrakis were not produced in this manner. A truly great storm occurred only when the ozone heat barrier was broken! Nefad almost recognized this fact. The strength of the ozone heat barrier depended upon the ultraviolet flux from Canopus, which varies. The strength of the cyclones varied also, but most important were the convective vortices. As we now know from the Rakis Finds, these were most prevalent during a daytime frontal passage. The stronger the cyclone the more vortices that were produced. Each vortex carried surface heat upward to the ozone barrier. On those occasions when conditions were right the heat transported upward could produce temperatures immediately below the ozone layer which were greater than that within the layer itself. The barrier was destroyed when this occurred. The reaction was self-perpetuating and explosive in its impact, and a truly great dust/sand storm evolved as the atmosphere in a real sense was overturned. Wind speeds as high as 800 kilometers per hour were recorded within these storms by certified instruments (which also managed to survive the storms' fury). Pachtra (10002) reported a single measurement of wind speed in excess of 1000 kilometers per hour. This is generally discredited since his instrument was out-of-certification at the time1. Additionally, such a speed would exceed the speed of sound, ground level, on Arrakis. Supersonic winds have never been confirmed on any planetary surface. Yet, as Ghralic so aptly puts it: "The residents of Arrakis reported fearfully loud noises during the greatest-storms. Could it be that the winds exceeded Mach -1 at times? The entire subject merits an attempt at laboratory duplication under controlled conditions." Electrical phenomena were an integral part of the surface environment. The dust whirls and storms generated considerable dust charging through tribo-electrification. Lightning discharges occurred frequently within the clouds and occasionally bolts struck the surface. Ozone was produced but this was only a minor contributor to total atmospheric ozone. Sand size (and larger) grains remained mostly in the lower levels of the Coriolis storms. Those closest to the surface caused severe erosion. If the planet were not so geologically active (see Arrakis — geology) its surface would have been entirely Hat except for the ubiquitous dune fields. During the decay phase of the storms much of the dust settled back onto the surface. Water vapor absorbed on the grains was carried downward also (a phenomenon locally called El-Sayal). Ionization by ultraviolet rays gradually released the water back to the atmosphere. Return was complete within a few days. Life Arrakis is the only planet in the system to harbor organic life forms. Life on Arrakis has been subject to harsh conditions during its history. It was discovered by the Society of Mystic Mariners under Jasta Mason. The star nearest the north celestial pole is the + 9 magnitude star Yuspen. Fauna *Laccifera arctica Sources *ARRAKIS category:planets